Endothelin is a naturally occurring hormone which is a potent vasoconstrictor. BMS-193884 is a highly selective endothelin (ET) receptor antagonist. The primary indication for this drug will be as an adjunct to standard-triple therapy (digoxin,diuretics, and angiotensin converting enzyme inhibitor [ACE])in the treatment of heart failure. Patients with severe heart failure have elevated plasma ET level. The magnitude of the elevated ET is positively correlated with New York Heart Association (NYHA) Functional Class and left ventricular end-diastolic volume. Plasma ET levels have also been shown to be inversely related to left ventricular ejection fraction, cardiac index, and survival. BMS-193884 has the potential to ameliorate the clinical signs and symptoms of heart failure by vasodilation. BMS-193884 selectively binds to and antagonizes the ET receptors responsible for vasoconstriction (ET). Tissue perfusion is improved. The primary objective of this study is to evaluate the dose related hemodynamic response of BMS-193884 in subjects with heart failure (NYHA II-IV and an EF <35%. This is a multicenter, randomized, double-blind, placebo-controlled trial designed to evaluate the hemodynamic effects and safety of a single oral dose of either 5,10,25,50,100, or 200 mg of the endothelin receptor antagonist BMS-193884 in patients with heart failure